Re: [PATCH v4 11/23] dt-bindings: Add RPMI system MSI message proxy bindings

[Anup Patel]

On Sat, Jun 7, 2025 at 4:29 AM Atish Patra <atish.patra@xxxxxxxxx> wrote:
>
>
> On 5/25/25 1:46 AM, Anup Patel wrote:
> > Add device tree bindings for the RPMI system MSI service group
> > based message proxy implemented by the SBI implementation (machine
> > mode firmware or hypervisor).
> >
> > The RPMI system MSI service group is defined by the RISC-V
> > platform management interface (RPMI) specification.
> >
> > Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
> > ---
> >   .../riscv,rpmi-mpxy-system-msi.yaml           | 67 +++++++++++++++++++
> >   1 file changed, 67 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,rpmi-mpxy-system-msi.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,rpmi-mpxy-system-msi.yaml b/Documentation/devicetree/bindings/interrupt-controller/riscv,rpmi-mpxy-system-msi.yaml
> > new file mode 100644
> > index 000000000000..26dd13731350
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,rpmi-mpxy-system-msi.yaml
> > @@ -0,0 +1,67 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/interrupt-controller/riscv,rpmi-mpxy-system-msi.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: RISC-V RPMI system MSI service group based message proxy
> > +
> > +maintainers:
> > +  - Anup Patel <anup@xxxxxxxxxxxxxx>
> > +
> > +description: |
> > +  The RISC-V Platform Management Interface (RPMI) [1] defines a
> > +  messaging protocol which is modular and extensible. The supervisor
> > +  software can send/receive RPMI messages via SBI MPXY extension [2]
> > +  or some dedicated supervisor-mode RPMI transport.
> > +
> > +  The RPMI specification [1] defines system MSI service group which
> > +  allow application processors to receive MSIs upon system events
> > +  such as P2A doorbell, graceful shutdown/reboot request, CPU hotplug
> > +  event, memory hotplug event, etc from the platform microcontroller.
> > +  The SBI implementation machine mode firmware or hypervisor) can
> nit:
> The SBI implementation in machine mode

Actually there should be a "(" just before "machine mode ...". I will
update in the next revision.

> > +  implement an SBI MPXY channel to allow RPMI system MSI service
> > +  group access to the supervisor software.
> > +
> > +  ===========================================
> > +  References
> > +  ===========================================
> > +
> > +  [1] RISC-V Platform Management Interface (RPMI)
> > +      https://github.com/riscv-non-isa/riscv-rpmi/releases
> > +
> > +  [2] RISC-V Supervisor Binary Interface (SBI)
> > +      https://github.com/riscv-non-isa/riscv-sbi-doc/releases
> > +
> nit: Refer the latest frozen version of the spec ?

Actually, we should specify the spec version number in the text
and avoid a specific link because the link of the final ratified version
will be different.

> > +properties:
> > +  compatible:
> > +    description:
> > +      Intended for use by the SBI implementation.
> > +    const: riscv,rpmi-mpxy-system-msi
> > +
> > +  mboxes:
> > +    maxItems: 1
> > +    description:
> > +      Mailbox channel of the underlying RPMI transport.
> > +
> > +  riscv,sbi-mpxy-channel-id:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description:
> > +      The SBI MPXY channel id to be used for providing RPMI access to
> > +      the supervisor software.
> > +
> > +required:
> > +  - compatible
> > +  - mboxes
> > +  - riscv,sbi-mpxy-channel-id
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    interrupt-controller {
> > +        compatible = "riscv,rpmi-mpxy-system-msi";
> > +        mboxes = <&rpmi_shmem_mbox 0x2>;
> > +        riscv,sbi-mpxy-channel-id = <0x2000>;
> > +    };
> > +...
>
> Otherwise, lgtm.
>
> Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
>

Regards,
Anup